Nigeria's President Muhammadu Buhari has appointed a committee to advise him on the best way to tackle corruption and reform the legal system, his spokesman said on Monday.

Buhari, who took office on May 29 after being elected on promises to fight endemic corruption, has said he believes officials have stolen around $150 billion from the public purse over the past decade.

"The committee's brief is to advise the present administration on the prosecution of the war against corruption and the implementation of required reforms in Nigeria's criminal justice system," said the president's spokesman, Femi Adesina.

He was unable to provide details of when the committee would report back to the president with its findings and recommendations.

Corruption and mismanagement of public funds have been entrenched in Nigeria's political system for decades.